Target-practice testing device



1929- i R. JARZABKIEWICZ El AL 1,730,370

TARGET PRACTICE TESTING DEVICE Filed Feb. 24, 1928 I71 Ven lars:

Patented Oct. 8, 1929 UNITE!) STATES,

,R'ATENI? ROMAN J'ARZABKIEWICZ, or TORUN, AND EDWARD WOJ'DATT, or IBEDZIN, POLAND l TARGET-PRACTICE 'IE STING DEVICE;

Application filed February 24, 1928, Serial No. 256,736,. and in roan Maren .1, "i927.

Our invention relates to apparatus for use in target practice and more especially for testing the accuracy of aiming, particularly with fire arms fixed to a stationary support and with blank cartridges. Heretofore the accuracy of aiming could not be tested when shooting with blank cartridges, so that it was necessary to provide target ranges involving considerable inconvenience and very high expense.

According to our invention these drawbacks are overcome and target ranges are dispensed with altogether. Blank cartridges can be used for practice, facilitating the testing of the accuracy and also reducing the cost of practice.

Our invention may be applied to all arms in which projectiles are expelled from a barrel by expanding gases and to arms of any 0 diameter of bore including rifles, machine guns, pieces of ordnance, etc.

In the drawing affixed to this specification and forming part thereof our invention is illustrated diagrammatically by way of example.

In the drawing Fig. 1 is a sectional elevation of the apparatus,

Fig. 2 is an end elevation and Fig. 3 is a section on the line IIIIII in Fig. 1.

Referring to the drawing, 1 is a gas chamber which is secured for instance .to the recoil intensifier or funnel (not shown) of a machine gun through which the projectile moves after leaving the barrel, 2 is an axial opening in the end wall of the chamber for the passage of the projectile, 3 are openings in the side wall of the chamber, 4 is a pipe connected to another opening in this chamber wall, 5 is a bend connected to the pipe 4, 6 is a cylinder connected to the bend 5 by means of a screw cap 7, 8 is a similar cap at the other end of the. cylinder, 9 is a sleeve connected with the cap 8, 10 and 11 are openings in the walls of the cylinder 6 and the cap 9, respectively, 12 is a piston adapted to reciprocate in the cylinder, 13 is a collar splined at 19 and fitted into the sleeve 13 on the rod 14: of the piston, 15 is a spring tending 0110151 the piston 12611 the cap 7, f

16 is-ajpoint'at the outer end of;thegpiston rod 14 and ,17 is a concave screen arranged in a frame 18 in fixed positi on so as not to be influenced by the movements of the machine The operation of our apparatus 'isas follows :Wl1en a shot has been fired, the powder gasesunder high-pressure enter the chamber, 1, are partly discharged through the openings 2. and 3, intothe open air, and partly into the pipe 4, forcing the piston 12 outwards against the action of spring 15, and causing the point 16 to mark a point on the screen 17 or on a paper attached thereto.

Upon the outward movement of the piston the openings 10 are laid open so that the gas can escape and spring 15 is able to return the piston 12 to its initial position. The openings 11 in the sleeve 9 and the splines 19 in 7 the collar 13 serve for removing any gas which might get into the outer .end of'the cylinder.

Instead of operating the apparatus in this manner, any part of a machine gun to which movement is imparted upon the firing of a shot, for instance the breech block, the bracket on which the barrel slides, or some other part may be utilized for moving the point 16 upon the firing of a shot, and suitable linkage, (not shown) may be provided for connecting the point with any such part- The concavity of the screen 17 is a func tion of the distance of the point 16 from the I vertical and horizontalpivot-s of the machine gun and the concavity is selected according to the accuracy of indications required.

In shooting practice each man receives a set of paper sheets which are inserted in the frame 18 of the screen 17 and on which the teacher marks two limiting points by which it is possible to compare and to examine exactly the vertical and horizontal deflections of the shots and to test the proficiency of each man. y

We wish it to be understood that we do not desire to be limited to the exact details of construction shown and described for obvious modifications will occur to a person skilled in the art. I

We claim:

1. An apparatus for testing the accuracy of aiming in shooting practice comprising a screen and means arranged to be mounted on the muzzle of a gun and to be influenced by the powder gases for marking on said screen the shots fired from fire arms.

2. An apparatus: for testing the accurac of aiming in connection with fire arms comprising a screen, a cylinder connected with a chamber accessible to/the' gas; discharged upon the firing of arms, a piston adapted to reciprocate in said cylinder, and} means on said piston for making a mark on said screen.

3. An apparatus for testing the accuracy of aiming connection with fire arms com.-

prising a screen, a gas collector adapted to p be secured to the muzz'l'es of fire-arms, a

cylinder, a gas pipe connected with said collector, a cylinder at the end of said gas pipe, a piston adapted to reciprocate in said cylinder, and means on said piston for marking a point on said" screen.

i In testimony whereof we afiix our signatures, Y

RG'MAN JARZABKI EWICZ'. EDWARD WOJDATT. 

